System of signaling and repeater therefor



July 19, 1932 E. E. KLEINSCHMIDT SYSTEM OF SIGNALNG' AND REPEATERTHEREFOR Filed Jan. 22, 1924 2 Sheets-Sheet l @Hoz we,

July 19, 1932 E. E. KLl-:lNscHMlDT SYSTE OF SIGNALING AND REPEATERTHEREFOR 2 sheets-Sheet 2 Filed Jan. 22, 1924 OOOOOOOOOOOOOOOOOOOOOOOOPatented July 19, A1932 UNITEDASTATES PATENT oFFIcE EDWARD E.KLEINSCHMIDT, OF LONG ISLAND CITY, NEW YORK, ASSIGNOR, :BY MESNEASSIGNMENTS, TO TELETYPE CORPORATION, F

TION OF DELAWARE CHICAGO, ILLINOIS, A CORPORA- SYSTEM OF SIGNALING ANDREPEATEB THEREFOR' Application led January 22, 1924. Serial No. 687,774.

The presentinvention relates to repeaters and re-transmitters forsignals, and a method of signaling.

More particularly the invention relates to a cable signaling system andto repeaters or re-transmitters adapted for the reception of more orless distorted and attenuated cable signals, and for the retransmissionof the received waves corrected in shape and amplified in strength. n

Heretofore more or less unsatisfactory devices have been proposed foreHecting repeating of cable signals by mechanical storing means.Correcting net works, wave filters yand thermionic amplifiers have als(`been proposed, but none have been suiiiciently satisfactory inoperationto meet the demand for a commercially satisfactory repeater andso far as known, no repeater has been of a character to reconstruct thespacing of the signals. The reason for the failure of prior devices hasbeen in a large measure due to failure to correct or reconstruct spacingand to complicated structures which have been slow and unreliable inoperation, diicult to maintain, and difficult to properly adjust. Thepractical impossibility of maintaining the proper speed relations of thetransmitter and the repeater over long sectionsfof cable in -themechanical repeaters heretofore proposed has contributed largely totheir failure in practice.

An object of the present system is to provide a new and improvedmechanical cable repeater or retransmitter, more simple in structure, ofgreater reliability, and more efficient than the devices heretoforeproposed. l

Another object of the invention is to provide a cable repeater of thecharacter de vscribed in which the distorted and attenuated waves fromthe cable are repeated in corrected and amplified form and withcorrected spacing, and in which the operations may be carried out athigher speeds than heretofore attainable.

A further object of the invention is the introduction into cableoperation of a new method or system of maintaining proper speedrelations between the transmitters and repeaters whereby reliabilityoperation is attained without the. necessity of using pomplicatedsynchronizing devices.

Stlll other objects of the invention are such as may be attained byutilization of the principles and apparatus set forth hereinafter in thedetailed description of the preferred embodiments of the invention.

Referring to the drawings:

Fig. 1 is a front elevation of the repeating arrangement with thetransmitting conf tacts and parts omitted.

Fig. 2 is a side.elevationfpartially in sec.- tion and with partsremoved to show the storing""eli/ents.

Fig. 3 is a plan view, partially in section showing the motor drive,clutch details and transmitting contacts.

Fig.' 4 is a showing more or less diagrammatic in nature of amodifiedarrangement of receiving magnets.

Fig. 5 is a diagram showing the circuit arrangement for a repeatingstation.

Fig. 6 shows a modified form of transmitting connection.

Fig. 7 shows perforated tape for cable transmission and the wave shapecorresponding therewith.

A motor 1 (Fig. 3) drives a pinion 2 which in turn drives a gear 3rigidly mounted on and drivin a shaft 4. Shaft 4 is suitably supported1n journals or bearings 5 and has mounted thereon a disc member 6 whichis rigidly secured thereto by means of a pin 7 or in any suitablevmanner'. Abutting against 6 is a disc 8 of friction material. A carriermember, preferably built up of a core 9 and end plates 10 and 11 rigidlybut detachably secured thereto in any convenient manner,

is mounted on shaft 4 1n a manner to be ro- A collar 14 is rigidlysecured v I to shaft 4 and a spring 15 between collar 14 i and disc 13forces the carrier and discs 12 and 8 against disc 6, forming` aconstantly engaged friction drive for the carrier.

A series of slots 16 (Fig. 2) are cut into core 9 of the carrier, andpivotally mounted in each of these slots is a storage member 17 (Figs. 2and Members 17 may be mounted on a ring 18 which fits in a circulargroove 19 cut into core 9 and intersect-ing slots 16. Ring 18 andmembers 17 are assembled as shown, and means may be inserted to prevent1S from shifting, and then end plate 11 is applied. lMembers 17 haveformed on the ends thereof cam members 21 which are composed preferablyof soft iron or easily magnetizable material. Cam members 21 are adaptedto be shifted to the right or left in paths 22 and 23 (Fig. 1) by rings24 and 25 and center piece 26.

Rings 24 and 25 are offset at 27 and 28 and fastened in a groove 29 ofsupport 30 by means of screws 31. Center piece 26 is supported from 30in any suitable manner as by screw 31 and extends between rings 24 and25 to divide the upper part of the space between these rings into twopaths for the movement of members 21. The lower part of rings 24 and 25is shaped so that the space between them gradually converges from theend of separate paths 22 and 23 at the left of Fig. 2 into a path 32which brings all of the members 21 to a central position before passingby the olfset portions. Rotation of shaft 4 moves the carrier throughthe friction discs and carries the cam members 21 around the paths 22,23 and 32.

As the members 21 pass out of path 32, they enter between pole pieces 34and 35 of magnets 36 and 37. CIf neither magnet 36 or 37 is energizedthe cam member 21 passing between the pole pieces 34 and 35 is held incentral position by means of light centering 38 or 39. y As 21 movesaway from the end of center piece 26, the carrier will commence torotate and 21 will pass into path 22 or 23 as the case may be.

As members 21 are rotated, immediately after leaving the stop positionand entering path 22 or 23 they will pass under, and cam roller 40 or 41and move the roller outward. Rollers 40 and 41 are mounted on pivotedarms 42'and 43 which carry contact springs 44 and 45. Contact springs 44and 45 carry contacts 46 and 47 adapted to engage contacts 48 and 49when rollers 4() and 41 are moved outward by cams 21. Springs 50 and 51Inormally hold arms 42 and 43 in a position with contacts 46 and 47disengaged and rollers 40 and 41 in inward position.

In Fig. 4 a modification of the magnet control of members 21 isshown.instead of directly attracting members 21 due to magnetic action,magnets 36 and 37, ,actuate plvoted armatures 50 and 51 which in turnpush members 21 into one or the other of paths 22 or 23. Springs 53 yand54 hold armatures 50 and 51 normally against adjustable stops and 56. Inthis form members 21 need not be of magnetizable material.

If desired cam members 21 may be permanent magnets and the shiftingthereof may be caused by the directions of current in windings 36 and 37in a well known manner. ln this case, rings 24 and 25 and center piece26 should preferably be of non-magnetic material, for example, bronze.

Mounted rigidly on shaft 4 is a disc 57 (Figs. 3, 5 and 6). Disc 58 isrotatably mounted on the shaft 4 and is secured to disc 57 by means ofan adjusting screw 59 extending through a slot therein. Discs 57' and 58have each formed on the periphery thereof eight teeth 6l and 62. Eachtooth is preferably of one-half of the angular width and slot 60 is soarranged that the angular distance covered by the teeth taken togethermay be adjusted to range from a halfof the angle of a cam 21 to the fullangle of a cam 21. A roller 63 carried by contact spring 64 is arrangedto be engaged and actuated by the edges of teeth 61 and 62 to closecontacts 65 and 66. The relative position of the teeth 61 and 62 withrespect to cams 21 is such that whenever the carrier comes to rest witha cam 21 against center piece 26, the contacts 65 andv 66 will be open.If desired, the angular position of disc 57 may also be made adjustableabout shaft 4, and to increase the range, the number of toothed platesmay be increased and the corresponding width of each tooth may bedecreased. As shown in Fig. 5, contact spring 64 may be provided with agrounding contact 67 which rests against a grounded contact 68 when therepeater is at rest and contacts and 66 are open.

Transmitting batteries 69 and 70 are connected from ground to contacts48 and 49 and adapted to be applied to the cable or line throughcontacts 46 and 47, arms 42 and 43,

conductors 71 and 72, conductor 73. contacts- 66 and 65, spring 64through lead 74 to the cable. The signals to be repeated are received onthe usual cable receiving relay 75. When a zero interval is received,armature 76 remains in mid-position` and when impulses are received,contact 78 or 79 is closed in accordance therewith, and battery 80 isapplied from the ground through magnets 37 or 38 to ground, and thecorresponding magnet is energized. l

In Fig. 5 a contact arrangement is shown whereby the cable is groundedduring no current or zero intervals, the purpose of which In this form yis well understood in the" art. In Fig. 6, a l' modication is shownwhere the connections 7 3 and 7 4 are reversed as indicated to avoidgrounding of thecable where such connec. tions are desired.

A'function of discs 57 and 58 and the contacts controlled thereby is tovary-the percentage of marking -time or length of the repeated impulses.By shortening the angular length of the combined teeth 61 and '62 agrounding, curbing,- or open circuit interval may be interposed betweeneach transmitted impulse, and the length of this interval may beadjusted to the constants lof the cable over which the repeater istransmitting. A further important result isattained in that thetransmitting circuit is made at contacts 65 and l 66 after the closingof contacts 46 to 49, and

is broken at the conta-cts 65. and 66 before v contacts 46 to 49 areopened. In this way all arcing occurs at contacts 65 and 66, andcontacts 46 to 49 may be made lighter and more delicate. The carrier andparts mounted thereon may therefore be light, and high speeds ofoperation may be attained. At a speed of 83 revolutions p er minute, 200words a minute may be repeated.

Methods of operation The preferred new method of operation comprises ingeneral the steps of driving each 'repeater or retransmitter preferablyat a slightly slower rate than the transmitter or repeater from which itis receiving; starting each repeater or retransmitter into operationA bythe rst incoming impulse, and thereafter maintaining it in operationwhile impulses are being received and as soon as a break in thereception of impulses occurs, stopping the repeater or retransmitteruntil impulses again come in. It will be understood thatl the brealreferred to which stops thetransmitter is longer than the usualgrounding or curbing interval between each impulse on the cable. Incable working an impulse of one polarity represents a dot, an impulse ofthe opposite polarity represents a dash, and a zero or no currentinterval as long vas or longerthan an impulse represents a space.

Although the continental code is generally used in which spaces or zerointervals as long as or'longer than an impulse occur only betweencharacters and words, theword spaces being longer than the letterspaces: other codes, as for example, letter combinations of dots, dashesand spaces of varying lengths, permutation codes,etc., may be used withequal facility and with no change in the structure of the repeatingapparatus, as will more fully hereinafter appear. Accordingly when azero interval of a length greater than the time of a normal curbing orgrounding interval betweenv impulses is received, as for example, aletter or word space in the continental code', the repeater is broughtto rest. As soon thereafter as animpulse of either polarity 'isreceived, the repeater is again started in operation and operatesuntil azero condition of suicient length is received.

l The repeater or retransmitter may also be operated at a faster ratethan the transmitter or repeaterfrom which it is receiving according toanother method of operation ofthe invention. In this case, the repeaterswill be stopped and started for each impulse received, and will remainat rest when the spaces are p being received and retransmitted.

In operating systems of the characterdescribed, or any signaling systemin which deiinite speed relations at widely removed points must bemaintained, the problem of speed regulation at remote points has beenconsidered heretofore a serious problem. Various forms of governingdevices-have been provided to maintain motors at suitably i constantspeeds of operation. I have discovered by experimentation that aninduction motor when driving a load which is only a small proportion'of' its rated capacity will operate with substantially no slip, andaccordingly will run at .substantially synchronous l speed. By usingover-size induction motors of alternating current may', in this manner,be utilized to replace the station speed governing devices otherwise`necessary. Where sources of alternatlng currentat the same fre-.quencies butof differing voltages are available at different stations,I have found that the slight speed difference resulting there.

from with standard motors, may be corrected by the use of adjustabletransformers inter` posed between the motor and the local power supply.This method o f driving apparatus by` use of over-size induction motorsresults in simplification' of station apparatus and in greaterreliability. It is obviously applicable loo to many types of systemssuch as various types of printing telegraph,- andselective systems.Having described the new methods of operation, the operation of theapparatus and retransmitting arrangements in accordance vwith thepreferred method of, operation will be set forth, the code'shown in Fig.7 being used for purposes of illustration. The motors at the variousstations are Vfirst set intov operation, and then tape 81 is inserted inthe transmitter at the transmitting station. A wave or impulse 82 issent to the line\and actul.one of the magnets 36 or 37 and the cammember 21 held against center piece or stop 26 is shifted to the rightor left. As soon as member 21 clears the center piece or stop member,the carrier Will start into rotation and the member 21 Will pass intopath 22 or 23 according to Which magnet is energized and Willimmediately pass under roller 40 or 41 and actuate contact 4G or 47 topartially close the repeating circuit. Shortly after this contact isclosed,.discs 57 and 58 operate to close contact 65 to send the impulseto the second section of cable and then openthis contact at the end ofthe impulse. Shortly after 65 has opened cam 21 moves completely pastthe roller 40 or 41 as the case may be, and contact 46 4or 47 is openedby the action of spring 50 or 51. As soon as the roller 40 or 41 dropsoif cam 21, the repeater is ready for the succeeding impulse. Thepreferred speed of operation is suoli that a succeeding impulse willarrive just before the succeeding cam member 21 reaches the stop shelfformed by the end of 26, and this cam member will be forced into path 22or 23 Without bringing the carrier to rest. Rotation Will thereforecontinue as long as impulses follow each other and retransmission ofeach impulse occurs immediately after it is received in the mannerdescribed. Then ay zero or no current line condition occurs as at' 83however, neither magnets 36 nor 37 will be energized'and the cani member2l coming between the magnets will remain in e central position afterleaving path 32, and will accordingly come to rest againstthe end of 26.Vhen the carrier comes to rest contacts 46 and 47 Will remain open and azero interval will be retransmitted and maintained until another signalimpulse is received. In this manner, it Will be seen that each zerosignal or longer interval brings the repeater torest, and during thistime a corresponding condition is maintained on the second section ofthe cable.

It Will be apparent that if the speed of the repeater is slightlyincreased, the carrier Will be started and stopped for each impulsereceived and will also remain at rest during the zero intervals. Thismethod of operation results in greater shock than the pre- 55,ferredmethod and for this reason is not so desirable.

Having described preferred embodiments of the invention, wvhat isdesired to\be secured by Letters Patent and claimed as new is:

1. ln a signaling system in which signal conditions made up of currentand no-current `intervals are utilized; a receiver comprising acontinuously rotating' motor; a rotary receiving member adapted to'bedriven by said motor; and means for causing said receiving member to bedriven by said motor when current intervals are received and forarresting rotation of said receiving member during no-current intervals.

.2. n a signaling system in Which signal tions of opposite polaritiesand spacing in-v tervals made up of no current conditions; a receivingmember; and means for permitting rotation of said receiving memberduring reception of a current condition of either polarity and forpreventing rot-ation of said member during the reception of a spacinginterval.

4. ln a signaling system comprising a receiver with a rotatable memberutilizing character signals made up of current conditions of oppositepolarities and spacing `in tervals between characters made up ofnocurrent conditions; the method of operation which comprises rotatingsaid receiver member in a single direction While current conditions ofeither polarity are received, and arresting rotation thereof Whileno-current conditions are received.

5. The method of maintaining ldefinite vspeed'relations of operatingtransmitter and receiver members which comprises operating thetransmitter at afixed speed, iinitiating the operation of a receivermember in respense to the first impulse of each signal,

operating the receiver at a speed slower than the speed of thetransmitter, and arresting the operation of the receiver member at thecompletion of each signal.

6. The method as set forth in claim 5 in which the transmitter isconstantly operated under solely local control at a uniform speed, andin which the rotation of the. receiver is under solely local controlbetween the starting and' stopping thereofpulsescoi'nprising a lrotarycarrier, a plurality of storing members mounted on said carrier, and astop adapted to be engaged byv .said storing members to arrest rotationof said carrier.

11.4The combination as set forth in claim 10 together with continuouslyoperating motor driven members to drive said rotary carrier.

` 12. The combination as set forth in claim 10 together withelectro-responsive means controlling said storing members and controlledby received signaling impulses. 13. In a cable signaling systemutilizing character signals made up of current conditions o oppositepolarity and spacing intervals made up of no current conditions, themethod of operation which comprises starting operation of areceiver'from a local-source under control of received currentconditions of either polarity and stopping'ope'rations thereof by thereception of a spacing interv val.

' ments mounted on a rotatable carrier for Yals 14. A repeatercomprising means for re.

ceiving attenuated` signals distorted in wave form and relative spacingof signals and means comprising avplurality of storing eletransmittingsaid signal amplified and corrected in wave form and spacing.

15. In a telegraph repeater, a receiver responsive to attenuated signalsa transmitter and a local source of mechanical energy controlled by saidreceiver Jfor operating said transmitter in a positive manner inaccordance with the operation of said receiver.

16.- In a telegraph system, a 'receiver responsive to attenuatedsignals, armature means responsive to the operation of said re-` ceiver,a source of mechanical energy and a transmitter operated by said sourceof mechanical energy' through said armature.

17. In a telegraphv system, a receiver, a local source ofpower forrotating said receiver under control o said received` im,v

pulses and means responsive to a Ii'o Icurrent condition for stoppingthejr'otation of .saidv receiver and a transmitter operated by"saidlocal source of power through said rotating receiver.

18. In a signaling system; a signal storingl means initiated andmaintained in operation by the reception'of signaling impulse conditionsand arrested in operation by the cessation of signaling; transmittingmeans actuated by said signal storing means to 'repeat the receivedsignaling impulse conditions comprising a plurality of transmittingcontacts operated in accordance with the received impulses; a secondcontact in series with said plurality of contacts; and means foroperating said second contact in a predetermined relation with respectto said plurality of contacts for completely regenerating the receivedimpulse conditions.

In a telegraph receiver; electro responsive means controlled by receiveddistorted impulse conditions; a signal storing means controlled by saidelectro -responsive means;

means'for initiating'and maintaining in operation said signal storingmeans by the reception of said distorted impulse conditions and forarrestingoperation of said. 'st0ring relation with respect to saidpluralityhof con- A tacts for completely 4regenerating said receivedimpulse conditions.AA l

20. In a receiver responsive to signaling` impulses comprising a rotarycarrier; a plu-1 ralityof storing members mounted on said carrier, a stop adapted to be engaged b said storing members to arrest rotation osaid carrier, a continuously operating motor driven member yfordriving'said rotarycarrier7 a transmitting circuit controlled therebycomprising a plurality of .transmitting contacts operated under controlof said 're-' c'eiverfor generating lcode combinations of marking andspacing impulse conditions, a second contact in serieswith saidplurality of contacts andmeans for operating said second contact in apredetermined relation with respect to said plurality of contacts yforconf trolling the wave shape of said marking and spacing im ul'seconditions.

21.|A `ca lerepeater comprisingla rotaryi carrier; aplurality of storingmembers,

mountedon said carrier; electrogresponsive 5 means "responsive todistorted received impulse conditionsv for variably operating saidstoring member;- a set of transmitting con# 'tacts controlled by saidstoring4 member; a

transmitting circuit controlled by said trans- 'notransmittingcircuit;and means for actuatmitting contacts; a timingcontact/fin said ing said timing -contact in' definitely `timed l' vrelationwith respectvto the operation of said transmitting 'contacts tocontrol the'length of the transmittedimpulses. A

22. Inga .cable signaling system utilizing character signals made up ofcurrent conditions'of oppositepolarity and spacing iny tervals made 'upof no current conditions; -f

.the method of operation which comprises starting operation of areceiver from a localv source under control of received impulse'convditions of eitheripolarity; 'stopping operations thereof during Zeroimpulse condition;

controlling 'a transmitter by said receiverfor transmittingcorresponding impulse conditions over a second cable; and periodicallygrounding the cable during intervals between the transmitted impulseconditions.

23. In a cablesignaling system utilizing character signals made up ofmarking current conditions of opposite polarity and no Current spacingconditionsgthe'method of operation which comprises starting operation ofa receiver from a local source under control of recelved currentcond1t1ons of" either polarity; stopping operations thereof during nocurrent conditions; retransmitting the received character signals inregenerated condition under local control and periodically grounding thecable intermediate each current condition. A

24. In a cable signaling system, the method of operating a repeaterwhich comprises' conditioning-the receiver forv response to an impulseby control ofv thepreceding impulse, whereby an impulse which follows aspace is repeated in nature and in time under control of thecorresponding received impulse and whereby an impulse which follows apreceding impulse is repeated in nature under control of the receivedimpulse and is repeated in time under control of the repeater.

25. The method of operating a receiver which comprises receiving signalimpulses at approximately uniform time intervals and conditioning thereceiver by each'impulsev to predetermine the manner of response to thenext succeeding impulse.

'26. In a telegraph system, a receiver responsive to received impulses,a transmitter, a local power means for operating said transmitter undercontrol ofvsaid receiver, and means in said receiver for repeating afirst impulse under control ofthe received impulse and for conditioningthe receiver to repeat a subsequent impulse in nature by control of thesubsequent impulse and in time by control of said local power means.

27. In a telegraph system in which groups of current-impulses areseparated by no-current intervals, the method of repeating whichcomprisestransmitting the first impulse of each group under controlofthe received impulse in nature land in time, and transmitting eachsubsequent impulse of each group under control of the received impulsein nature and under control of the repeater in time.

In testimony whereof, I aflix my signature.

EDWARD E. KLEINSCHMIIDT.

